Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
1.
Adv Mater ; : e2402628, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38670114

RESUMO

A new nanoporous amorphous carbon (NAC) structure that achieves both ultrahigh strength and high electrical conductivity, which are usually incompatible in porous materials is reported. By using modified spark plasma sintering, three amorphous carbon phases with different atomic bonding configurations are created. The composite consisted of an amorphous sp2-carbon matrix mixed with amorphous sp3-carbon and amorphous graphitic motif. NAC structure has an isotropic electrical conductivity of up to 12 000 S m-1, Young's modulus of up to ≈5 GPa, and Vickers hardness of over 900 MPa. These properties are superior to those of existing conductive nanoporous materials. Direct investigation of the multiscale structure of this material through transmission electron microscopy, electron energy loss spectroscopy, and machine learning-based electron tomography revealed that the origin of the remarkable material properties is the well-organized sp2/sp3 amorphous carbon phases with a core-shell-like architecture, where the sp3-rich carbon forms a resilient core surrounded by a conductive sp2-rich layer. This research not only introduces novel materials with exceptional properties but also opens new opportunities for exploring amorphous structures and designing high-performance materials.

2.
J Healthc Eng ; 2022: 4285197, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35368944

RESUMO

Total hip arthroplasty (THA) and total knee arthroplasty (TKA) are effective methods for the treatment of end-stage osteoarthritis. Furthermore, rehabilitation training and psychological interventions play significant roles in the recovery of hip and knee joint function after THA and TKA. A total of 46 patients who received hip replacement and knee replacement are equally divided into two groups, with the control group being prescribed routine rehabilitation intervention and the observation group prescribed an early rehabilitation pathway with Morita therapy intervention. According to the results, the observation group displayed a significantly decreased incidence of deep venous thrombosis, while simultaneously reducing the recovery time of lower limb function (P < 0.05), including straight leg raising time, walking time, and vertical knee flexion time. In addition, the treatment program demonstrates a significant ability to improve the joint function score, pain score, quality of life score, and range of motion score (P < 0.05). Moreover, serum D-dimer, fibrin degradation products (FDP), and femoral vein blood flow peak also are significantly reduced (P < 0.05). Therefore, we have determined that an early rehabilitation pathway combined with Morita therapy can effectively reduce stress pain, improve the recovery process of joint motor function, and reduce the incidence of thrombosis. However, an increased sample size would facilitate the confirmation of the safety and efficacy of the program. In addition, the overall financial expenditure and feasibility of the treatment need to be considered.


Assuntos
Artroplastia de Quadril , Artroplastia do Joelho , Artroplastia do Joelho/reabilitação , Humanos , Qualidade de Vida , Amplitude de Movimento Articular
4.
ACS Nano ; 14(6): 7280-7286, 2020 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-32427466

RESUMO

Defect-free graphene is impermeable to gases and liquids but highly permeable to thermal protons. Atomic-scale defects such as vacancies, grain boundaries, and Stone-Wales defects are predicted to enhance graphene's proton permeability and may even allow small ions through, whereas larger species such as gas molecules should remain blocked. These expectations have so far remained untested in experiment. Here, we show that atomically thin carbon films with a high density of atomic-scale defects continue blocking all molecular transport, but their proton permeability becomes ∼1000 times higher than that of defect-free graphene. Lithium ions can also permeate through such disordered graphene. The enhanced proton and ion permeability is attributed to a high density of eight-carbon-atom rings. The latter pose approximately twice lower energy barriers for incoming protons compared to that of the six-atom rings of graphene and a relatively low barrier of ∼0.6 eV for Li ions. Our findings suggest that disordered graphene could be of interest as membranes and protective barriers in various Li-ion and hydrogen technologies.

5.
Clin Exp Reprod Med ; 46(3): 132-139, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31405270

RESUMO

OBJECTIVE: Vitamin D-binding protein (VDBP) mediates various biological processes in humans. The goal of this study was to investigate whether VDBP gene polymorphisms could predispose Korean women to endometriosis. METHODS: We prospectively enrolled women with endometriosis (n = 16) and healthy controls (n = 16). Total serum 25-hydroxyl vitamin D (25(OH)D) concentrations were measured using an Elecsys vitamin D total kit. Levels of bioavailable and free 25(OH)D were calculated. Concentrations of VDBP were measured using a vitamin D BP Quantikine ELISA kit. DNA was extracted using a DNeasy blood & tissue kit. Two singlenucleotide polymorphisms (SNPs; rs4588 and rs7041) in GC, the gene that codes for VDBP, were analyzed using a TaqMan SNP genotyping assay kit. The functional variant of VDBP was determined based on the results of the two SNPs. RESULTS: Gravidity and parity were significantly lower in the endometriosis patients than in the control group, but serum CA-125 levels and the erythrocyte sedimentation rate were significantly higher. Total serum 25(OH)D levels in the endometriosis patients were significantly lower than in the control group. However, serum bioavailable 25(OH)D, free 25(OH)D, and VDBP levels did not differ significantly between the endometriosis and control groups. The genotypes and allele frequencies of GC were similar in both groups. CONCLUSION: Korean women with endometriosis had lower total serum 25(OH)D concentrations than controls. Neither serum VDBP concentrations nor polymorphisms in the gene coding for VDBP were associated with endometriosis. Further studies are needed to investigate the pathophysiology and clinical implications of 25(OH)D and VDBP in endometriosis.

6.
Clin Exp Reprod Med ; 46(3): 125-131, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31370113

RESUMO

OBJECTIVE: To investigate serum 25-hydroxyl vitamin D (25(OH)D) and vitamin D-binding protein (VDBP) concentrations in women with endometriosis according to the severity of disease. METHODS: Women with mild endometriosis (n = 9) and advanced endometriosis (n = 7), as well as healthy controls (n = 16), were enrolled in this observational study. Serum total 25(OH)D concentrations were analyzed using the Elecsys vitamin D total kit with the Cobas e602 module. Concentrations of bioavailable and free 25(OH)D were calculated. Concentrations of VDBP were measured using the Human Vitamin D BP Quantikine ELISA kit. Variables were tested for normality and homoscedasticity using the Shapiro-Wilk test and Leven F test, respectively. Correlation analysis was used to identify the variables related to total 25(OH)D and VDBP levels. To assess the effects of total 25(OH)D and VDBP levels in the three groups, multivariate generalized additive modeling (GAM) was performed. RESULTS: Gravidity and parity were significantly different across the three groups. Erythrocyte sedimentation rate (ESR) and CA-125 levels increased as a function of endometriosis severity, respectively (p= 0.051, p= 0.004). The correlation analysis showed that total 25(OH)D levels were positively correlated with gravidity (r = 0.59, p< 0.001) and parity (r = 0.51, p< 0.003). Multivariate GAM showed no significant relationship of total 25(OH)D levels with EMT severity after adjusting for gravidity and ESR. However, the coefficient of total 25(OH)D levels with gravidity was significant (1.87; 95% confidence interval, 0.12-3.63; p= 0.040). CONCLUSION: These results indicate that vitamin D and VDBP levels were not associated with the severity of endometriosis.

7.
Clin Exp Reprod Med ; 45(3): 143-148, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30202745

RESUMO

OBJECTIVE: The favored method of preserving fertility in young female cancer survivors is cryopreservation and autotransplantation of ovarian tissue. Reducing hypoxia until angiogenesis takes place is essential for the survival of transplanted ovarian tissue. The aim of this study was to investigate the role of angiopoietin-1 (Angpt-1), angiopoietin-2 (Angpt-2), and vascular endothelial growth factor (VEGF) in ovarian tissue grafts that were cryopreserved using two methods. METHODS: Ovarian tissues harvested from ICR mice were divided into three groups: group I (control), no cryopreservation; group II, vitrification in EFS (ethylene-glycol, ficoll, and sucrose solution)-40; and group III, slow freezing in dimethyl sulfoxide. We extracted mRNA for VEGF, Angpt-1, and Angpt-2 from ovarian tissue 1 week following cryopreservation and again 2 weeks after autotransplantation. We used reverse transcriptase-polymerase chain reaction to quantify the levels of VEGF, Angpt-1, and Angpt-2 in the tissue. RESULTS: Angpt-1 and Angpt-2 expression decreased after cryopreservation in groups II and III. After autotransplantation, Angpt-1 and Angpt-2 expression in ovarian tissue showed different trends. Angpt-1 expression in groups II and III was lower than in group I, but Angpt-2 in groups II and III showed no significant difference from group I. The vitrified ovarian tissues had higher expression of VEGF and Angpt-2 than the slowfrozen ovarian tissues, but the difference was not statistically significant. CONCLUSION: Our results indicate that Angpt-2 may play an important role in ovarian tissue transplantation after cryopreservation although further studies are needed to understand its exact function.

8.
PLoS One ; 13(5): e0196550, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29768438

RESUMO

BACKGROUND: The association of a higher body mass index (BMI) with better survival is a well-known "obesity paradox" in patients on hemodialysis (HD). However, men and women have different body compositions, which could impact the effect of BMI on mortality. We investigated the effect of gender on the obesity-mortality relationship in Korean patients on HD. METHODS: This study included 2,833 maintenance patients on HD from a multicenter prospective cohort study in Korea (NCT00931970). The relationship between categorized BMI and gender-specific mortality was evaluated by an adjusted Cox proportional hazard model with restricted cubic spline analyses and the Competing risk analysis. We also investigated the effect of changes in BMI over 12 months and serum creatinine level on survival in male and female patients on HD. RESULTS: The mean BMI was 22.6 ± 3.3 kg/m2 and the mean follow up duration was 24.2 ± 3.4 months. The patients with the highest quintile of BMI (≥25.1 kg/m2) showed lower mortality (subdistributional hazard ratio [SHR] = 0.63, 95% confidence interval [CI] = 0.43-0.93, P = 0.019) compared with those with the reference BMI quintile. When analyzed by gender, male patients with a BMI over 25.1 kg/m2 had lower mortality risk (HR = 0.43, 95% CI = 0.25-0.75, P = 0.003); however, no significant difference was found in female patients. Increased BMI after 12 months and high serum creatinine were associated with better survival only in male patients on HD. CONCLUSIONS: BMI could be used as a risk factor for mortality in male patients on HD. However, the mortality of female patients on HD was not related with baseline and follow-up BMI. This suggests that BMI is a good surrogate marker of lean body composition, especially in male patients on HD.


Assuntos
Índice de Massa Corporal , Creatinina/sangue , Diálise Renal/mortalidade , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Estimativa de Kaplan-Meier , Falência Renal Crônica/complicações , Falência Renal Crônica/mortalidade , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/mortalidade , Modelos de Riscos Proporcionais , Estudos Prospectivos , República da Coreia/epidemiologia , Fatores de Risco , Fatores Sexuais
9.
J Korean Med Sci ; 33(18): e135, 2018 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-29713255

RESUMO

BACKGROUND: Although intracavitary radiotherapy (ICR) is essential for the radiation therapy of cervical cancer, few institutions in Korea perform 3-dimensional (3D)-based ICR. To identify patients who would benefit from 3D-based ICR, dosimetric parameters for tumor targets and organs at risk (OARs) were compared between 2-dimensional (2D)- and 3D-based ICR. METHODS: Twenty patients with locally advanced cervical cancer who underwent external beam radiation therapy (EBRT) following 3D-based ICR were retrospectively evaluated. New 2D-based plans based on the Manchester system were developed. Tumor size was measured by magnetic resonance imaging. RESULTS: The mean high risk clinical target volume (HR-CTV) D90 value was about 10% lower for 2D- than for 3D-based plans (88.4% vs. 97.7%; P = 0.068). Tumor coverage did not differ between 2D- and 3D-based plans in patients with tumors ≤ 4 cm at the time of brachytherapy, but the mean HR-CTV D90 values in patients with tumors > 4 cm were significantly higher for 3D-based plans than for 2D-based plans (96.0% vs. 78.1%; P = 0.017). Similar results were found for patients with tumors > 5 cm initially. Other dosimetric parameters for OARs were similar between 2D- and 3D-based plans, except that mean sigmoid D2cc was higher for 2D- than for 3D-based plans (67.5% vs. 58.8%; P = 0.043). CONCLUSION: These findings indicate that 3D-based ICR plans improve tumor coverage while satisfying the dose constraints for OARs. 3D-based ICR should be considered in patients with tumors > 4 cm size at the time of brachytherapy or > 5 cm initially.


Assuntos
Imageamento Tridimensional , Planejamento da Radioterapia Assistida por Computador , Neoplasias do Colo do Útero/radioterapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Braquiterapia , Feminino , Humanos , Imageamento por Ressonância Magnética , Pessoa de Meia-Idade , Órgãos em Risco/efeitos da radiação , Dosagem Radioterapêutica , Estudos Retrospectivos , Neoplasias do Colo do Útero/diagnóstico por imagem , Neoplasias do Colo do Útero/patologia
11.
Kidney Res Clin Pract ; 36(2): 200-204, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28680828

RESUMO

Administration of autologous mesenchymal stem cells (MSCs) has been shown to improve renal function and histological findings in acute kidney injury (AKI) models. However, its effects in chronic kidney disease (CKD) are unclear, particularly in the clinical setting. Here, we report our experience with a CKD patient who was treated by intravenous infusion of autologous MSCs derived from adipose tissue in an unknown clinic outside of Korea. The renal function of the patient had been stable for several years before MSC administration. One week after the autologous MSC infusion, the preexisting renal insufficiency was rapidly aggravated without any other evidence of AKI. Hemodialysis was started 3 months after MSC administration. Renal biopsy findings at dialysis showed severe interstitial fibrosis and inflammatory cell infiltration, with a few cells expressing CD34 and CD117, 2 surface markers of stem cells. This case highlights the potential nephrotoxicity of autologous MSC therapy in CKD patients.

12.
Korean J Intern Med ; 32(3): 505-513, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-27017390

RESUMO

BACKGROUND/AIMS: There may be an association between vitamin D levels and allograft outcomes in kidney transplant recipients (KTRs). However, few studies have been conducted to determine the association between vitamin D levels and post-transplant infections. This study investigated the impact of vitamin D deficiency on the risk of infection after kidney transplantation. METHODS: We measured 25-hydroxyvitamin D (25(OH)D) levels prior to kidney transplantation. Vitamin D deficiency was defined as a serum 25(OH)D level < 20 ng/mL. We examined the incidence of various post-transplant infections during follow-up period. We used Cox proportional hazards regression analysis to determine factors associated with increased risk of post-transplant infections during the follow-up period. RESULTS: A total of 164 KTRs were followed up for a mean of 24.8 ± 10.7 months. Among them, 135 patients (82.3%) had vitamin D deficiency. Patients with vitamin D deficiency had a significantly higher incidence of urinary tract infection (p = 0.027) and any bacterial infection (p = 0.010) compared to those without vitamin D deficiency. Vitamin D deficiency was not significantly associated with incidence of viral or fungal infections. Cox proportional hazards regression analysis revealed that vitamin D deficiency (hazard ratio, 11.07; 95% confidence interval, 1.46 to 84.03; p = 0.020) was independent risk factor for post-transplant bacterial infections. CONCLUSIONS: Pre-transplant vitamin D deficiency was a significant risk factor for bacterial infections after kidney transplantation. Further studies are needed on possible benefits of vitamin D supplementation for preventing post-transplant bacterial infection.


Assuntos
Infecções Bacterianas/etiologia , Transplante de Rim/efeitos adversos , Complicações Pós-Operatórias/etiologia , Deficiência de Vitamina D/complicações , Adulto , Infecções Bacterianas/epidemiologia , Feminino , Rejeição de Enxerto/etiologia , Humanos , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , República da Coreia/epidemiologia , Estudos Retrospectivos , Fatores de Risco
13.
Medicine (Baltimore) ; 96(48): e8769, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29310352

RESUMO

Obesity is a well-established risk factor for cardiovascular disease (CVD), but the underweight population of body mass index (BMI) below 18.5 kg/m has not been an object of concern. The objective of this study is to investigate whether underweight could be an independent risk factor for CVD in a population-based cross-sectional study.Cross-sectional data of 2013 Behavioral Risk Factor Surveillance System (BRFSS) database encompassing 491,773 US adult subjects were used to assess risk for CVD. Primary outcomes were the incidence and relative risks (RRs) of CVD including stroke, heart attack/myocardial infarction, or coronary artery disease according to BMI category. All analyses used weighted sampling probabilities of data source.The underweight population had a 19.7% greater risk of CVD than did the normal-weight, and the overweight and obese population had a 50% and 96% increased risk, respectively. When adjusted with covariates, the relative risk for CVD elevated in underweight population (adjusted RR 1.34 [95% confidence interval (CI) 1.335-1.348]). Conversely, the adjusted relative risk was significantly attenuated in the obese group (adjusted RR 1.149 [95% CI 1.147-1.151]) and it was even insignificant in the overweight group (adjusted RR 1.00 [95% CI 1.000-1.003]). In subanalysis for each CVD category, being underweight among BMI status was the strongest independent risk factor for stroke (adjusted RR 1.441 [95% CI 1.431-1.450]), heart attack/ myocardial infarction (MI) (adjusted RR 1.23 [95% CI 1.217-1.233]), and angina/coronary artery disease (adjusted RR 1.20 [95% CI 1.189-1.206]). Especially among the population below 40-year old, relative risk estimates remained increased in the underweight population; persons who were underweight had a 2.3-fold greater adjusted relative risk of CVD as compared with those with normal weight when we stratified with age.Underweight below BMI 18.5 kg/m may be another risk factor for CVD, and CVD risk of the overweight and obese population largely depended on other comorbidities accompanied by obesity.


Assuntos
Doenças Cardiovasculares/epidemiologia , Magreza/epidemiologia , Adolescente , Adulto , Idoso , Sistema de Vigilância de Fator de Risco Comportamental , Índice de Massa Corporal , Estudos Transversais , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Medição de Risco , Fatores de Risco , Estados Unidos/epidemiologia
14.
Int J Gynecol Cancer ; 26(4): 711-5, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26905333

RESUMO

OBJECTIVE: The aim of the study was to evaluate the efficacy of the levonorgestrel intrauterine system (LNG-IUS) for treatment of endometrial hyperplasia (EH). METHODS: A prospective multicenter study was conducted from November 2010 to March 2014. Patients with histologically confirmed EH were treated with LNG-IUS. At 3, 6, and 9 months after LNG-IUS insertion, follow-up endometrial aspiration biopsies with the LNG-IUS in the uterus were undertaken. At the 12th month of follow-up, endometrial tissues were obtained via 2 methods: endometrial aspiration biopsy with the LNG-IUS in the uterus, followed by dilatation and curettage (D&C) after LNG-IUS removal. The primary outcome was the regression rate at 12 months after LNG-IUS insertion, and the secondary outcome was the consistency of the results between the endometrial aspiration biopsy and the D&C. RESULTS: The study population comprised 75 patients, including 37 with simple hyperplasia without atypia; 3 with atypical simple hyperplasia; 23 with complex hyperplasia without atypia, and 12 with atypical complex hyperplasia. Of these patients treated with the LNG-IUS, 38 (50.7%) were followed up at 12 months after LNG-IUS insertion. The complete regression rate at 12 months was 94.7% (36/38): 100% (6/6) of patients with atypical EH and 93.7% (30/32) with EH without atypia. In all of the cases (100%, 36/36), patients achieved complete regression within 3 months of LNG-IUS insertion. A comparison of the pathologic results from endometrial aspiration biopsy and D&C was carried out for 15 patients. In the histologic results by endometrial aspiration biopsy, 14 patients were diagnosed as "normal endometrium" and 1 as "insufficient tissue for pathologic evaluation." Among the 14 cases of normal endometrium by endometrial aspiration biopsy, 1 was diagnosed as "residual EH" by D&C, and the 1 case with insufficient tissue was diagnosed as normal endometrium by D&C. CONCLUSIONS: Levonorgestrel intrauterine system is an effective and favorable method for treatment of EH.


Assuntos
Anticoncepcionais Femininos/administração & dosagem , Hiperplasia Endometrial/tratamento farmacológico , Dispositivos Intrauterinos Medicados/estatística & dados numéricos , Levanogestrel/administração & dosagem , Adulto , Biópsia por Agulha Fina , Gerenciamento Clínico , Hiperplasia Endometrial/patologia , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Prospectivos , Adulto Jovem
15.
Obstet Gynecol Sci ; 59(1): 75-8, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26866042

RESUMO

Iatrogenic parasitic myomas are rare. The condition is defined by the presence of multiple smooth-muscle tumorous nodules in the peritoneal cavity. This may be attributable to seeding of myoma particles during uterine surgery. The clinical course is usually indolent. The disease is often asymptomatic and is usually discovered only incidentally. A 38-year-old woman who had undergone abdominal myomectomy 7 months prior presented with acute abdominal pain and a huge pelvic mass. We performed exploratory laparotomy. A parasitic mass 17 cm in diameter with a twisted omental pedicle was identified. En bloc excision of the mass and omentum was performed, followed by total abdominal hysterectomy. Histopathological examination of multiple sections revealed features compatible with an infarcted leiomyoma. Thus, we present a very rare case of an iatrogenic, rapidly growing parasitic myoma complicated by omental torsion (which caused the acute abdominal pain). We also offer a literature review.

16.
Korean J Intern Med ; 31(5): 930-7, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26867084

RESUMO

BACKGROUND/AIMS: Little is known regarding the incidence rate of and factors associated with developing chronic kidney disease after continuous renal replacement therapy (CRRT) in acute kidney injury (AKI) patients. We investigated renal outcomes and the factors associated with incomplete renal recovery in AKI patients who received CRRT. METHODS: Between January 2011 and November 2013, 408 patients received CRRT in our intensive care unit. Of them, patients who had normal renal function before AKI and were discharged without maintenance renal replacement therapy (RRT) were included in this study. We examined the incidence of incomplete renal recovery with an estimated glomerular filtration rate < 60 mL/min/1.73 m(2) and factors that increased the risk of incomplete renal recovery after AKI. RESULTS: In total, 56 AKI patients were discharged without further RRT and were followed for a mean of 8 months. Incomplete recovery of renal function was observed in 20 of the patients (35.7%). Multivariate analysis revealed old age and long duration of anuria as independent risk factors for incomplete renal recovery (odds ratio [OR], 1.231; 95% confidence interval [CI], 1.041 to 1.457; p = 0.015 and OR, 1.064; 95% CI, 1.001 to 1.131; p = 0.047, respectively). In a receiver operating characteristic curve analysis, a cut-off anuria duration of 24 hours could predict incomplete renal recovery after AKI with a sensitivity of 85.0% and a specificity of 66.7%. CONCLUSIONS: The renal outcome of severe AKI requiring CRRT was poor even in patients without further RRT. Long-term monitoring of renal function is needed, especially in severe AKI patients who are old and have a long duration of anuria.


Assuntos
Injúria Renal Aguda/terapia , Anuria/terapia , Hemodiafiltração/métodos , Injúria Renal Aguda/fisiopatologia , Anuria/fisiopatologia , Humanos , Incidência , Testes de Função Renal , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo
17.
Korean J Intern Med ; 31(1): 106-15, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26767864

RESUMO

BACKGROUND/AIMS: This study analyzed the risk factors for technique survival in dialysis patients and compared technique survival rates between hemodialysis (HD) and peritoneal dialysis (PD) in a prospective cohort of Korean patients. METHODS: A total of 1,042 patients undergoing dialysis from September 2008 to June 2011 were analyzed. The dialysis modality was defined as that used 90 days after commencing dialysis. Technique survival was compared between the two dialysis modalities, and the predictive risk factors were evaluated. RESULTS: The dialysis modality was an independent risk factor predictive of technique survival. PD had a higher risk for technique failure than HD (hazard ratio [HR], 10.8; 95% confidence interval [CI], 1.9 to 62.0; p = 0.008) during a median follow-up of 11.0 months. In the PD group, a high body mass index (BMI) was an independent risk factor for technique failure (HR, 1.3; 95% CI, 1.0 to 1.8; p = 0.036). Peritonitis was the most common cause of PD technique failure. The difference in technique survival between PD and HD was more prominent in diabetic patients with a good nutritional status and in non-diabetic patients with a poor nutritional status. CONCLUSIONS: In a prospective cohort of Korean patients with end-stage renal disease, PD was associated with a higher risk of technique failure than HD. Diabetic patients with a good nutritional status and non-diabetic patients with a poor nutritional status, as well as patients with a higher BMI, had an inferior technique survival rate with PD compared to HD.


Assuntos
Falência Renal Crônica/terapia , Diálise Renal , Adulto , Idoso , Índice de Massa Corporal , Humanos , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/mortalidade , Masculino , Pessoa de Meia-Idade , Estado Nutricional , Diálise Peritoneal/efeitos adversos , Diálise Peritoneal/mortalidade , Estudos Prospectivos , Diálise Renal/efeitos adversos , Diálise Renal/mortalidade , República da Coreia , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
18.
Obstet Gynecol Sci ; 58(5): 391-6, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26430664

RESUMO

OBJECTIVE: Revascularization is critical for successful ovarian tissue transplantation. Vascular endothelial growth factor (VEGF) and angiopoietin-2 (angpt-2) are the principal mediators of neovascularization. This study was designed to assess VEGF and angpt-2 levels in cryopreserved ovarian tissue after heterotopic autotransplantation. METHODS: Ovarian tissues harvested from ICR mice at 5 to 6 weeks of age were stratified as follows: no cryopreservation (controls, group I); vitrification in VFS-40 (vitrification, group II); and gradual freezing in dimethyl sulfoxide (slow-freezing, group III). Frozen specimens were thawed at room temperature, assaying VEGF and angpt-2 levels 1 week after cryopreservation and 2 weeks after autotransplantation. RESULTS: VEGF and angpt-2 protein levels were significantly lower in cryopreserved ovaries of groups II and III than in controls (group I, P<0.05), whereas groups II and III did not differ significantly in this regard. After autotransplantation of cryopreserved ovarian tissue, VEGF and angpt-2 protein levels did not differ significantly by technique but tended to be lower than corresponding levels in controls. CONCLUSION: Expression of angiogenic factors in ovarian tissue is thought to vary by method of cryopreservation. Our findings indicate that levels of angiogenic factors expressed in cryopreserved ovarian tissue after autotransplantation do not differ appreciably from control levels, regardless of cryopreservation technique.

19.
Nano Lett ; 15(1): 319-25, 2015 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-25493357

RESUMO

Reactivity control of graphene is an important issue because chemical functionalization can modulate graphene's unique mechanical, optical, and electronic properties. Using systematic optical studies, we demonstrate that van der Waals interaction is the dominant factor for the chemical reactivity of graphene on two-dimensional (2D) heterostructures. A significant enhancement in the chemical stability of graphene is achieved by replacing the common SiO2 substrate with 2D crystals such as an additional graphene layer, WS2, MoS2, or h-BN. Our theoretical and experimental results show that its origin is a strong van der Waals interaction between the graphene layer and the 2D substrate. This results in a high resistive force on graphene toward geometric lattice deformation. We also demonstrate that the chemical reactivity of graphene can be controlled by the relative lattice orientation with respect to the substrates and thus can be used for a wide range of applications including hydrogen storage.


Assuntos
Grafite/química , Modelos Químicos , Dissulfetos/química , Molibdênio/química , Dióxido de Silício/química , Compostos de Tungstênio/química
20.
Ther Apher Dial ; 18(6): 628-36, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25256793

RESUMO

Encapsulating peritoneal sclerosis (EPS) involves excessive peritoneal fibrosis in patients on peritoneal dialysis, eventually leading to visceral constriction and bowel obstruction. Few studies have investigated epigenetic mechanisms relating to EPS. Here we evaluated the therapeutic effects of DNA demethylation in experimental EPS. Experimental EPS was induced by intraperitoneal injection of 0.1% chlorhexidine gluconate (CG) and 15% ethanol in non-uremic male Sprague-Dawley (SD) rats. Rats were divided into three groups: group C (N=5) with saline injection only, group CG (N=7) with EPS induction for 4 weeks, and chlorhexidine gluconate and azacytidine (CGA) treated group (N=7) with EPS induction for 4 weeks and 5'-azacytidine injection for the last 2 weeks. Morphometric analysis of peritoneum and immunohistochemical staining for type 1 collagen and α-smooth muscle actin (α-SMA) were performed. Expressions of transforming growth factor-ß (TGF-ß), fibroblast-specific protein 1 (FSP1), and DNA methyltransferase 1 (DNMT1) were analyzed by Western blot. Methylation-specific polymerase chain reaction (PCR) for Ras GTPase activating-like protein 1 (RASAL1) was performed with measurement of RASAL1 protein expression. Parietal peritoneal thickness and the number of vessels in omental tissue were significantly decreased in group CGA compared to group CG, as were the expressions of type 1 collagen, α-SMA, TGF-ß, and FSP1. DNMT1 was significantly increased in group CG, and reduced in group CGA. RASAL1 hypermethylation was associated with decreased RASAL1 protein expression in group CG, which was reversed in group CGA. DNA demethylation by 5'-azacytidine treatment improved pathologic changes of the peritoneum in experimental EPS, and was associated with reversal of increased DNMT1 expression and RASAL1 hypermethylation.


Assuntos
Azacitidina/farmacologia , Metilação de DNA , Diálise Peritoneal/efeitos adversos , Fibrose Peritoneal/fisiopatologia , Animais , Clorexidina/análogos & derivados , Clorexidina/toxicidade , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/genética , Modelos Animais de Doenças , Etanol/toxicidade , Regulação da Expressão Gênica , Masculino , Fibrose Peritoneal/etiologia , Fibrose Peritoneal/genética , Ratos , Ratos Sprague-Dawley , Proteínas Ativadoras de ras GTPase/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...